Bobbin case opener driving mechanisms



Sept. 18, 1956 G. GOEBEL BOBBIN CASE OPENER DRIVING MECHANISMS 2 Sheets-Sheet 1 Filed March 4, 1954 INVENTOR. Gregory Goebel ATTORNEY Sept. 18, 1956: G. Gol-:BEL 2,763,226

I BOBBIN CASE OPENER DRIVING MECHNISMS Filed March 4. 1954 2 Sheets-Sheet 2 INVENTOR. Gregory Goebel WITNESS Mdd@ @ww ATTORNEY United States 2,763,226 BOBBIN CASE OPENER DRIVING MECHANISMS Gregory Goebel, Trumbull, Conn., assignor to The Singer Manufacturing Company, Elizabeth, N. J., a corporation of New Jersey Application March 4, 1954, Serial No. 414,049

2 Claims. (Cl. 112-184) This invention relates to .a driving mechanism for a sewing machine loop-taker and, more particularly, to a gear drive conjointly actuating a vertical axis rotary hook and a bobbin-case opener mechanism.

It is an object of this invention to provide a gear drive which may be incorporated within a frame or saddle in which both the hook and the bobbin case are carried 4as a unit.

It is a further object of this invention to provide a gear drive of .the above character in which .the timing of the rotary hook with respect to the needle may be adjusted readily and without disturbing the timed relation between the rotary hook and the bobbin-case opener mechanism.

With the above Iand other objects and advantages in view as will hereinafter appear, this invention comprises the devices, combinations and arrangements of parts hereinafter described and illustrated in the accompanying drawings in which:

Fig. l is a side elevational view of a portion of a sewing machine, partly in vertical section and having my invention applied thereto;

Fig. 2 is an enlarged top plan View of one hook saddle of the sewing machine illustrated in Fig. l

Fig. 3 represents a vertical sectional view of the hook saddle taken substantially along line 3 3 of Fig. 2; and

Fig. 4 represents a vertical sectional view of the hook saddle taken substantially along line 4-4 of Fig. 2.

Referring particularly to Fig. l, the present invention has been embodied in a two-needle lock-stitch sewing machine. This machine has a frame comprising a bed from one end of which rises a standard 11 which supportsv a bracket-arm terminating in a sewing head 12 which overhangs the bed. Journaled for endwise reciprocation in the sewing head 12 is a needle-bar 13 which has clamped at its lower end two needles 14 and 15 that are spaced from each other lengthwise of the bed 10. Also journaled for vertical movement in the head 12 is a spring depressed presser-bar 16 carrying at its lower end a conventional presser-foot 17.

A lthroat-plate 18, which is carried by the bed beneath the presser-foot 17, is apertured to accommodate penetration by the needles and is slotted in the usual manner to receive a feed-dog 19 which is supported beneath `the bed and given rising and falling movements by a feed-lift eccentric 20 which is carried by the usual bed-shaft 21. In addition to Ithese rising and falling movements, an adjustable eccentric 22 also carried by the bed-shaft 21 serves, as is well known in the art, to impart advance and return movements to the feed-dog transversely of the bed to feed the material being stitched with respect to the needles.

The mechanism for reciprocating the needles is not shown in the drawings, however, any conventional needlereciprocating means may be employed. The bed-shaft 21 is driven, as by a belt 23, in timed relation with the needlereciprocating means, that is, with the bed-shaft completing one revolution for each cycle of needle reciprocation.

to the respective needles 14 and 15 in the formation of lock-stitches, are vtwo loop-takers 26 and 27 comprising conventional vertical axis rotary hooks each having a needle-thread loop-seizing beak 28. Journaled in each of the rotary hooks 26 and 27 is a bobbin-case carrier 29 which is adapted to receive a bobbin (not shown) upon which is wound the lower or locking thread. The rotary hook in the usual way is adapted to cast a loop of needlethread about the locking thread on the bobbin, thereby .to form the usual lock-stitch. Each bobbin-case carrier 29 is formed with a rotation-restraining nose 31 which projects between spaced stop lugs 32-32 depending from the throat-plate 18 to prevent the bobbin-case carrier from rotating with the hook. Each bobbin-case carrier is also formed with a radially extending ear 33 that forms a part of the bobbin-case opener mechanism which, as will be presentedly described, serves periodically to rock the bobbin-case carrier so as to provide `a clearance space for passage of the loop of needle-thread between the rotationrestraining nose 31 and the stop lugs 32-32.

Each of the rotary hooks 26 and 27 is carried in a separate support bracket or saddle 34 and 35, respectively, and each of the saddles also carries a bobbin-case opener mechanism. As shown in Fig. 2, the saddles are each adapted .to be supported beneath the bed 10 and to that end each is provided with a split boss 36 clamped by a screw 37 upon one of the bushings 38 and 39 in which the bed-shaft 21 is journaled. The saddles are also slotted, as at 40, each .to accommodate a fastening screw 41 which is threaded into the machine bed. When the screws 37 and 41 are loosened, therefore, the saddles may be relocated lengthwise of the bed, as for instance, to reposition the hooks for cooperation with a different lateral spacing of needles 14 and 15.

The hook saddles, as best illustrated in Fig. 4, are each formed at one side of the split collar 36 with a concavity extending horizontally across the saddle and dening in the saddle vertically spaced bearing lugs 43 and 44. The saddles are also provided each with a shallow oil pan 45 which is fitted beneath the saddle and has a gasket 46 therebetween to provide a lubricant-containing reservoir 47.

Since the arrangement of the rotary hook, the bobbincase opener mechanism, and the driving mechanism therefor are similar in each of the hook saddles save that each is of the opposite hand, a description of the right hand hook saddle 35 of Fig. 1, which isillustrated in detail in Figs. 2, 3 `and 4 will apply equally well to both saddles. The rotary hook 27 is carried by a hook shaft 50 which is journaled on a vertical axis in bearings 51 and 52, one in each of the vertically spaced bearing lugs 43 and 44 of the hook saddle. Adjacent the hook shaft and also journaled on a vertical axis in bearing bushings 53 and 54 is a bobbin-case opener driving shaft 55. A crank pin 56 formed at the upper extremity of the opener driving shaft 55 is connected by a link 57 to one arm of a bell-crank lever 58 that is journaled for oscillatory movement on a raised boss 59 which surmounts the saddle 35. A linger 60 which is secured to the bell-crank lever 58 is disposed periodically to engage the ear 33 which projects from the bobbin-case carrier `and in this manner to rock the bobbincase and shift -the nose 31 clear of the stop lugs 32-32 for unobstructed passage of the needle-thread therebetween.

In the present invention, the rotary hook 27 and the screw is seated l'in r ay lor groove 6-3 formed in 4the rbed-'sha'ftso that .gear 61 may beshifted .conveniently along .the shaft A.without :angular'shift =of the .gear about the shaft Whenever lateral adjustment is made of the position of Ithe hook saddle.

Meshing with the spiral driving :gear '61 is a spiral :pinion 64 which is carried by the hook shaft .50 and is lmade 'fast thereto by set screws such tas :that shown at vr65. The pinion 64 -is one-half .the size lof fthe driving :gear 61 so that the hook will be rotatedat twice the speed ofthe bedshaft 21 and, therefore, 'the hook will partake of two Arevolutions for each .cycle `of .reciprocation-.of the needles ras Yis conventional in Vrotary hook machines. The set screws 65 of the pinion 64 are accessible by virtue of a `slot .66 formed in the bearing lug ,431of :the hook saddle, as shown in Fig. 4, and the timing of athejh'ook with respect @to kthe needle may be accomplished by loosening 'the set screws 65 and Yadjusting the .rotary Shook .and the hook shaft with respect tothe pinion 64.

Carried on the hook shaft .50 beneath .and independently of the pinion .64 is a bobbin-case :opener driving spur gear 67 which is made -fast to the hoo'k lshaft :as fby set screws 68. Meshing with the driving spur gear '67 is a spur gear 69 `which is 4made fast to the bobbin-'case opener drive shaft .55, -as 'by set screws '70. fGear 69 lis preferably twice .the size of the opener driving gear V67 :so that the bobbin-case opening finger .'60 will be oscillated into operative engagement with .the -ear 33 on the bobbincase carrier with tthe same frequency as the needle reciprocation, i. ie., once for every two revolutions of the rotary hook.

In the operation of a rotary hook withV a -bobbin-case opening mechanism, a `definite timing relationship must exist between the rotation of the hook and the `oscillation of the opener finger. This will be self evident when it "is understood that the thread Vis cast about the bobbin-case by the hookrand, therefore, .the :action of `the hook-dictates the .proper :instant :at which the -bobbin case should be opened .or shifted eclear of .the rotation-restraining lugs. In the present invention the timing -o'f the bo'bbin-case opener mechanism with the rotary hook1is insured since the hook shaft 50 .and the .opener drive Vshaft 55 are interrelated with a positive mechanical driving `connection in the form of the set `of gears 67 and 69. `I-n contrast with all vof .the prior 'bobbin-:case opener driving constructions, the present invention provides .a timing -connection Jbetween the rotary hook .and the bobbin-case 'opener mechanism ywhich once properly set, .as Vby adjustment of gears 67 and 69 on their respective shafts, will not be disturbed by any of the other adjustments 'to the hook or fthe book saddle which may be necessary for proper stitch formation.

One of the most common of these adjustments is the lateral adjustment `of the entire hook saddle as when the hook saddle is to be shifted along the bed shaft 21 to .accommodate a change in spacing between the needles. This adjustment is accomplished by loosening the saddle fastening screw 41 and the .clamp screw 37 as well as the set `screw 62 of the spiral driving gear ^61 'and 'then -by shifting the saddle together with the spiral driving gear 61. During this adjustment the .timed relation between the hook .and the opener vmechanism remains undisturbed.

Still another adjustment, that of the hook timing with respect to the reciprocation of the needle, may lbe yaccomplished in .two .ways neither .of which .alter 4the Atiming .be-

tween the hook and the opener mechanism when the machine is equipped with the present improvement. Timing of the hook with the needle may be accomplished by loosening the set screw and angularly adjusting the spiral pinion 64 on the hook shaft. Fine adjustments of hook timing with respect to the needle may also be effected :by 'shifting .the spiral driving .gear .61 lengthwise of the bed-shaft .for a small amount. Because of the spiral shape o'f the gear teeth, this bodily shifting of the gear 61 provides for a micrometer adjustment of hook timing.

Since none of the above described adjustments of the hook position xor timing affects the meshing interconnection of gears 67 and 69, the present invention provides a construction in which the bobbin-case opener mechanism when properly timed will remain in the desired timed relation with the hook.

Having .thus set forth the 4nature .of the invention, .what I claim herein is:

1. A .rotary A,hook :mechanism assembly adapted to be detachably secured .as va'unit to a sewing machine .havling .a rotary actuating shaft and a driving gear mounted on said :actuating shaft, comprising, a supporting saddle, a rotary hook-'shaft :journaled in said supporting saddle, a rst gear mounted on said hook-shaft and adapted to mesh with ysaid driving gear lon said actuating shaft, a rotary hook carried by .said hook-shaft, means for securing said tirstgear in aselected one of a plurality of positions angularly .of said hook-shaft, a bobbin case carrier journaled in said rotary hook, :an .opener-finger supported on said saddle for movement into and out of engagement with said bobbin'case carrier, .a rotary opener-shaft journaled in said saddle and .operatively connected to said openerfinger, a lgear on said opener-shaft, a second gear mounted on said hook-shaft .and meshing with the gear on said opener-shaft, and means ffor securing said ysecond gear in selected position angularly of said hook-shaft.

2. A rotary hook mechanism assembly adapted to be dctachably secured as ka unit to a sewing machine having a horizontally disposed rotary actuating shaft and a driving gear mounted -on said actuating shaft, comprising, a supporting saddle, a rotary hook-shaft journaled vertically in said supporting saddle, an upper gear mounted -on said hook-shaft and adapted 'to mesh with said driving gear .onsai'd .actuating shaft, means for securing said upper gear ina selected one of .a plurality of positions vangularly of said hook-shaft, a rotary hook carried by said hookshaft, albobbin-case carrier journaled in said rotary hook, an opener-linger supported on said saddle for movement into and outof engagement with said bobbin-case carrier, a rotary .opener-shaft journaled in `said saddle in subs-tantially parallel relation with said hoek-shaft and operatively connected Ato said opener-linger, a gear on said opener-shaft, a lower gear mounted on said hookshaft tbelow Isaid upper gear and meshing with the gear on said opener-shaft, and means other than that lfor adjustably securing said upper gear for securing said -lower gear :in aselected one ofa plurality of positions angular-ly of said hook-shaft.

References Cited in the file of this patent Ul\II"1`I-D STATES PATENTS 1,298,074 McPherson Mar. 25, 19.19 2,476,061 Parry July 12, 1949 2,712,802 Cottrell July 12, 1955 

